Top 10 Inpatient Diagnoses by DRG Codes

Updated August 2019

Outpatient care has been in the spotlight for healthcare providers and regulators like the Centers for Medicare and Medicaid Services (CMS). Ambulatory surgery centers and retail clinics are gaining popularity with patients for being low-cost, convenient alternatives to primary care physicians and emergency departments. CMS is regularly updating its list of inpatient-only procedures and shifting reimbursement guidelines as medical technology advances, allowing patients to receive surgeries such as joint replacements in outpatient facilities.

However, inpatient revenue still constitutes a significant percentage of hospitals' total patient revenues. Of the hospitals with the highest total patient revenues, inpatient earnings were greater for 6 of the top 10 according to Definitive Healthcare data. The top ten most common primary inpatient diagnoses were reported a total of 9.5 million times in 2018. The ten most common secondary diagnoses were reported over 105 million times.

Top 10 Primary Diagnoses by DRG Code

Fig 1 Annual Medicare Data is from the Centers for Medicare and Medicaid Services (CMS) Medicare Standard Analytical Files (SAF).Data above reflects calendar year 2018 through December. Complete calendar year data is projected to be released each fall by the CMS. The most recent data is from calendar year 2017; 2018 data is scheduled to be released in fall 2019. All-Payor Estimates are based on Definitive Healthcare calculations and algorithms.

A "primary" diagnosis is established by a physician as the principal reason for a patient's admittance and governs a patient's initial course of treatment. The "secondary" diagnosis, or diagnoses as the case may be, are any condition that exist alongside the primary diagnosis at the time of admission, or that affect a patient's care after the initial diagnosis. The most common secondary diagnosis is, by far, "septicemia or severe sepsis" (DRG code 871). Septicemia, also called sepsis, is a severe blood infection that is most often contracted via wound infection. If left untreated, sepsis can lead to organ damage, organ failure, and even death. Sepsis is relatively common with an annual estimate of 30 million cases per year. It often presents as a hospital-acquired infection (HAI). 

There is significant overlap between the most common primary and secondary inpatient diagnoses. Psychoses, major joint replacement, sepsis, heart failure, and pulmonary edema & respiratory failure are some of the most commonly occurring conditions, and can be diagnosed simultaneously or as the result of another condition on the list. If a patient is admitted for a joint replacement, they could conceivably contract sepsis while in recovery, which could lead to heart and/or respiratory failure. Every primary diagnosis listed, with the exception of DRG codes 794 and 795 (neonate with significant problems and normal newborn), are diagnosed far more often as secondary diagnoses. While these conditions may be the initial reason for a patient visit, they are most commonly the result of underlying conditions or procedure complications.

Top 10 Secondary Diagnoses by DRG Code

Fig 2 Annual Medicare Data is from the Centers for Medicare and Medicaid Services (CMS) Medicare Standard Analytical Files (SAF).Data above reflects calendar year 2018 through December. Complete calendar year data is projected to be released each fall by the CMS. The most recent data is from calendar year 2017; 2018 data is scheduled to be released in fall 2019. All-Payor Estimates are based on Definitive Healthcare calculations and algorithms.

In the most recent reporting year, sepsis made up more than 7 percent of total inpatient diagnoses in the U.S., followed by heart failure (4 percent) and psychoses (3 percent).

Visit the Definitive Blog to read about the top outpatient diagnoses, top hospitals by outpatient claims, or download our Definitive List to discover the top inpatient procedures by ICD-10 code.

Definitive Healthcare is the leading provider of most up-to-date, comprehensive data on over 8,800 hospitals & IDNs, 1.6 million physicians, and dozens of other healthcare providers. Sign up for a free trial today!